Question

Find the cost of leveling a triangular field of sides 32 m, 48 m and 60 m at the rate of Rs 150 per m2. a Rs 19800 b Rs 198000 c d Rs 178000


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Answer 1

Answer:

Ncert exemplar solutions

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Mathematics

Science

Chapters in Mathematics Exemplar Problems - class 9

Exercises in Heron's Formula

Question 1

Find the cost of laying grass in a triangular field of sides 50 m, 65 m and 65 m at the rate of Rs 7 per m².

Solution

Transcript

According to the question,

Sides of the triangular field are 50 m, 65 m and 65 m.

Cost of laying grass in a triangular field = Rs 7 per m²

Let a = 50, b = 65, c = 65

s = (a + b + c)/2

⇒ s = (50 + 65 + 65)/2

= 180/2

= 90.

Area of triangle = √s(s-a)(s-b)(s-c)

= √90(90-50)(90-65)(90-65)

= √90×40×25×25

= 1500m²

Cost of laying grass = Area of triangle ×Cost per m2

= 1500×7

= Rs.10500